1. Field of the Invention
The invention relates to collapsible back supports. More particularly, the invention relates to a collapsible back support for use with wheelchairs, wherein the back support includes a unique cross construction forcing an individual to sit in an upright position.
2. Background of the Invention
Back supports provided with wheelchairs must be collapsible to permit folding and storage of the wheelchair when the chair is not in use. Currently, wheelchair back supports are manufactured from a flexible sheet of material, hammock, secured between a pair of upwardly extending support posts at the rear of the wheelchair. While these back supports are flexible, thus permitting an individual to readily fold the chair, they fail to provide the back support needed by individuals confined to a wheelchair for a prolonged period of time. In fact, these back supports encourage bad posture resulting in the discomfort caused by lower back problems.
In fact, there is a growing consensus among health-care practitioners that poor posture is a leading cause of the illness and disease related to back problems and pressure sores. Improper posture can actually rupture discs, and practitioners have stated that poor sitting posture is one of the major factors, and definitely the most ignored factor, in the etiology of pressure sores.
The design of back supports is one of the leading causes of back problems, especially in the case of wheelchairs. Because of the need for collapsibility, wheelchairs are typically constructed with vinyl or fabric hammocks seats and back rests. Even under the most ideal circumstance, i.e., when these fabrics are stretched tightly across the support members, the weight of the user will cause the fabric to stretch over time. As a result, pressures on the body are distributed unevenly causing the body to sit obliquely. Eventually, what begins as sitting discomfort due to slouching, eventually leads to the development of pressure sores and herniated discs.
These problems can be solved by providing a support surface capable of supporting normal lordosis in the lumbar spine. This is achieved by keeping the pelvis rotated forward. In fact, it has been shown that eight times more intradiscal pressure is created when a person assumes a kyphotic, or backward (i.e., slouching), sitting posture. Further, when an individual slouches the center of gravity rides behind the pelvis and the sitting bones do not take the direct pressure of sitting. Instead there is a sheering force against the sitting bones and occasionally even pressure on the tailbone and sacrum when the pelvis has rolled back. These uneven pressures often lead to pressure sores in wheelchair users.
Similar problems occur in conventional chairs utilizing straight backs as a support for a seated individual's back. Many straight back seats inherently encourage individuals to slouch, resulting in bad posture and lower back pain. This problem is exaggerated in collapsible chairs when the back support must be collapsible to accommodate the collapsing mechanism used by the chair. As with wheelchairs, such collapsible chairs often utilize flexible sheets secured between the upstanding support posts extending from the seat member. These flexible sheets do not provide the back support necessary to ensure proper posture.
In view of the shortcomings of back supports currently available, there continues to be a need for an adjustable back support providing the support required by individuals who must be in a seated position for extended periods of time. The present invention overcomes the shortcomings of prior back supports by providing a stable, collapsible, and adjustable back support for use with collapsible wheelchairs, or other collapsible chairs.